There are many instances in which a mesh (e.g. a wire mesh) is used to support, anchor, reinforce or shape a hardenable material such as plaster or concrete or certain curable plastics. One such use is in the constructure of stucco walls.
In the construction of stucco walls, it is common to attach a moisture barrier such as a building paper to a wall and then fasten a wire mesh or other perforate material over the building paper. Subsequently, the soft or uncured stucco is applied over the wire mesh lath and allowed to harden in place to thereby become firmly bonded to the wire mesh and anchored to the wall. A number of variations of this process have been suggested and used.
However, the increasingly high labor costs for field application of wire mesh and building paper have forced lath manufactures to devise ways of combining the two at the factory so that they can be applied to studs or furring strips or sheathing in one direction. In one example of such a composite, a welded, rectangular wire lath is joined with building paper by means of a mechanical interlocking system in which horizontal wires of the netting were sandwiched between a sheet of uncoated kraft paper and a sheet of building paper that was bonded to the kraft paper after positioning the wires. Perforations in the kraft paper exposed the horizontal wires and those exposed wires were welded to vertical wires to mechanically form the paper/rectangular wire lath composite. In another type of composite, parallel wires were sandwiched between kraft paper and building paper. Intermittently, the wires projected through the kraft paper so that they could later be twisted with and thereby interlocked with a hexagonally patterned wire mesh.
Continuing attempts have been made to reduce the cost of stucco lath manufacture by producing improved composite products. More recently, one product has been developed which has gained commercial significance in the U.S. In that product, building paper is bonded to a wire mesh or lath by means of small shots of hot melt adhesive applied at intervals over one of the twisted wires which make up the wire lath to thereby directly bond the wire mesh to the paper web. In a typical instance, about (4) one-gram shots of hot melt adhesive would be used per square foot of composite. Although this type of composite is a significant improvement over some of the earlier composites, it is not without its problems. Among the various problems that have been reported are the following:
(1) The system is relatively more expensive than desired.
(2) The hot melt adhesives must be carefully selected. If the hot melt adhesives are too soft at elevated temperatures, the composite can delaminate under hot summer conditions. On the other hand, if the hot melt adhesives are too hard at low temperatures, they will tend to crack under cold winter conditions.
(3) The commercially used spacing of the hot melt adhesives allows some motion of the paper away from the lath so that excessive amounts of stucco are sometimes required to cover the lath adequately. More adhesive could be used, but this would increase costs and increase the problems described in subparagraph 4 hereof.
(4) Sometimes the hot melt adhesives used on the mesh so rigidly hold the mesh to the backing paper that if the backing paper becomes very dry in a hot afternoon summer sun the paper can shrink to such an extent that the resulting stresses exceed the strength of the bonding system and failure occurs either in the paper or in the hot melt adhesive, or at the interface of the two.
(5) Current manufacturing processes used in making this type of composite are relatively slow (e.g. 50 feet per minute).
Accordingly, there exists a need for an improved composite which would reduce or eliminate some of the problems associated with prior art composites.